I've been forgetting to update the solar cycle and solar-terrestrial indices for a while. I mean I last updated this last December 29 and that update was even later than this.
A highlight I've posted on solar cycle updates has been the "Last solar cycles comparison" from Space Weather News, and produced by a group called solen.info. NOTE: the plot is at the first link, not the second (solen.info). Here is the current plot:
It's pretty obvious that cycle 25, 2nd from the bottom (that is, 2nd weakest), peaked a little before the 60 months after cycle start line and the current reading is vertically between cycle 24 (weakest in the last hundred years) and cycle 22 (the black curve) which was in 1986-1996. What's not quite as obvious at first glance is the highest Smoothed Sunspot Numbers (SSNs) of cycle 25 are well above cycle 24, the previous cycle, on the bottom everywhere, but what you can't see on this graph is that cycle 24 had the lowest SSNs in the last hundred years, so cycle 25 has been quite a bit more active than 24 but that's just not saying much. "Hey, we're not the worst cycle in a hundred years!"
Let's look at Cycle 25's raw data, note the first two vertical lines on the left (2018 and 2020) are still cycle 24:
You'll notice that the absolute peak of cycle 25 occurred during 2024. There were some days with very high solar flux in '24: the highest peak was in August as shown here: each black dot is one month. That peak was a highlight in the last post because that was around the time that I got closer to hearing Alaska on 6m as I ever have. Everything I've ever heard about working Alaska from guys around here is it's pretty much a "once in a lifetime" thing. During that "band opening" I never copied a single letter from Alaska, but a friend in Tennessee copied one 15 second transmission from the Alaskan.
Is there a chance of hearing Alaska down here again in what's left of cycle 25? My guess is that if the current trend holds, almost a smaller and mirror image of cycle 21, then no. The only thing that I think would help the chance of getting Alaska is for a second peak of SSN, equal to or stronger than the previous peak forms. A second peak would completely wipe out the right side (prediction) of the SSN for the rest of the cycle. The only hope would be that the SSN in the time I heard Alaska was well after that peak of the cycle in August. The November/December time frame I heard Alaska in is that short little straight line two dots after the August peak.
SiG - does solar activity directly impact the climate? There is a lot of pro and con information floating around out there.
ReplyDeleteCan't say I've paid much attention to those talks but I lean toward it probably has some effect on climate.
DeleteI tend to think of climate as something that's determined by long term averages - like a hundred years - and in the weather sense, the sun affects everything. That turns the question into whether some sort of long term average of some part of solar radiation affects long term weather.
The plots of solar activity we have go back pretty much to the time of Galileo, and the periods are much shorter than a hundred years. There just doesn't seem to be much consistency between solar cycles. The odd fact is the ability to determine when a sunspot cycle is starting or ending is something discovered in the last 20 years, so the records aren't consistent.
When you look at something like reconstructions of climate going back thousands or millions of years, like I post for earth day either the sun has dramatically changed or something else is affecting the climate. Long before humans.
There is some evidence that cosmic radiation may affect both weather and climate. During the minima of the solar cycles there is an increase in cosmic radiation. Cosmic radiation is believed to help create the nuclei that causes cloud formation. With increased cosmic radiation there are more clouds formed. Unfortunately this is not well researched as it goes against the narrative that humans are the major forcing factor in bad weather and climate change.
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